Before diving into the perpetual calendars let’s take a brief look at the Gregorian and Julian calendars.
The Gregorian calendars are known as the Western and Christian calendars, these are also internationally accepted. The calendar has 365 days with an extra day every four years.
The Julian calendar has two types of years, a normal year consisting of 365 days as well as a leap year of 366 days. It’s primarily used by astronomers, and in software, so they can easily calculate days between two events.
A Perpetual calendar can be used for several years. It’s designed to look up a day of the week for a specific time. These calendars advance the day, date, and year correctly until the year 2100, taking into account any leap years, 28-days in February, and the difference between 30 and 31-day months. After 2100 the date then needs to be adjusted by one day on 1 March 2100. The same applies to the years 2200 and 2300. The perpetual calendar also typically indicates the year, moon phase, and highlights a leap year indicator.
The Three Variations Of Perpetual Calendars
The Perpetual calendar has three variations. The first one is a 14 one-year calendar, there is a table to show which one-year calendar is going to be used for a given year. These one-year calendars divide into two sets of seven calendars, seven for each usual year (that means the year that does not have a February 29) with each of the seven starting on a different day of the week, and seven for each leap year (That has a February 29).
The second variation contains seven one-month calendars and one or several tables to show which calendar is used for a given month. The seven calendars may be combined into one, either with 13 columns of which only seven are revealed.
The third variation is basically the combination of the first two variations. A one-year calendar in which the names of the months are fixed and the days of the week and dates are shown on movable pieces which can be swapped around as necessary.
The First Perpetual Calendar in Use
Thomas Mudge is known as the man who invented the perpetual calendar in 1762. It was a gold pocket watch that contained the calendar, and it can be viewed up to this day at the British Museum. It took a long time to adopt it into wristwatches. In 1925 Patek Philippe made the first wristwatch with the perpetual calendar. They used a pocket watch movement and put it into a wristwatch. These Perpetual calendars featured watches basically know if it’s a 30 or 31-day month or if there is a leap year and adjust the date correctly.
Patek Philippe designs and manufactures movements and timepieces. It has an uninterrupted watchmaking history since its founding. They are also one of the oldest watch manufacturers. They have one of the most complicated mechanical watches.
Patek has the best reputation in watches that features perpetual calendar because they were the first to make it happen. However, the first timepiece that featured a perpetual calendar and was made with a wristwatch mechanism was made by Breguet in 1929.
The watch was sold in 1934 to Monsieur Jean Dollfus. He bought the watch for his brother for his 500th flying hour and with that became an experienced pilot. He bought it for 11,000 CHF.
Perpetual calendar watches got really popular after Patek made the “1526” watch in 1941. At the time this was the only perpetual calendar wristwatch in production on the market. This watch is extremely rare and highly desirable. It was offered in yellow gold, pink gold, and there is a steel one as well. The case back is engraved, “Mario P. Nigra July 30th, 1952.” Only 210 pieces were made, the majority of that number were made in yellow gold.
Patek has a bunch of timepieces that feature a perpetual calendar, but they are very expensive as well. There are other brands that make perpetual calendar watches like Jaeger.
Jaeger Master Ultra Thin
It’s a classic, elegant Perpetual timepiece from Jaeger that has an extremely thin case, and is only available in Jaeger-LeCoultre boutiques.
The case is available from different materials, but the one that we can see above is made out of 18 carats of pink gold and has a diameter of 39 mm. It has a water resistance level of 5 bar (50 meters / 164 feet). The dial is silvered grey and it's sunray brushed with gilt hour markers. The dial is available in different colors if we choose the stainless steel case.
The strap is made from black leather, but it can be changed to any other strap. The lug width is 21mm with a length of 75mm and 120mm. It has a pin buckle made from 18 carats of pink gold that has an 18mm width.
The movement is an automatic winding, and it has 28800 vibrations per hour and 46 jewels with 38 hours of power reserve.
It reimagines traditional complications with designs that feature-rich, clean lines.
“The Perpetual Calendars”
We’ve gone through how Perpetual calendars play a role in wristwatches and who was the one who invented it. It makes it easy and convenient that people don’t have to bother with changing the dates manually. There will be brands that are most likely will keep making them for this reason.